It is known that animals such as dogs have good sensitivity to odours, with dogs being up to 200 times more sensitive to smell than humans. Such animals can be trained to respond in a particular detectable way to a specific odour. Trained sniffer dogs, for instance, are used to detect explosives, illegal drugs etc.
It is also known that insects can have much greater sensitivity to odours and can be more sensitive than the best physical techniques including gas chromatography, possibly being sensitive to odiferous materials present at very low levels down to 10−18 molar. Insects including bees, wasps, moths, aphids, etc can be trained or conditioned to respond with high accuracy and specificity to a specific odour in a detectable manner e.g. by measuring electrical signals in antennae (electroantennography) or observing physical movements such as proboscis extension. For instance, forager honey bees (species Apis mellifera) can be conditioned to a particular target odour, making a readily visible reflex proboscis extension response (see, e.g., Pham-Delegue M.-H., Bailez O., Blight M. M., Masson C., Picard-Nizou A. and Wadhams L. J. (1993) Behavioural discrimination of oilseed rape volatiles by the honeybee Apix mellifera L. Chem.senses 18: 483-494.).
Hitherto, insect responses of this sort have been generally only monitored in laboratories, e.g. for experimental purposes. Insects are not robust so practical difficulties arise over handling and transport of insects for use in other than laboratory conditions.
The present invention aims to facilitate wider use and exploitation of insect odour sensing abilities.